THURSDAY, May 22, 2014 (HealthDay News) -- Deaf children with cochlear implants are at increased risk for developmental delays in memory and higher thinking, a new study finds.

A cochlear implant is an implanted device that helps provide a sense of sound to people who are deaf or have severe hearing loss, according to the U.S. National Institute on Deafness and Other Communication Disorders.

This study included 73 deaf children who received cochlear implants before they were 7 years old and 78 children with normal hearing. All of the children in the study had average to above-average IQ scores.

Compared to children with normal hearing, those with the cochlear implants were two to five times more likely to have delays in memory, planning, attention and conceptual learning, processes collectively known as executive functioning.

But the Indiana University research team also discovered that earlier implantation of a cochlear device reduced that risk. Children who got the implants at an average age of 18 months had fewer delays in executive functioning than those who were implanted at an average age of 28 months.

The researchers also found that many deaf children develop average or better executive functioning skills after receiving a cochlear implant, according to the study published May 22 in the Journal of the American Medical Association Otolaryngology--Head and Neck Surgery.

"Cochlear implants produce remarkable gains in spoken language and other neurocognitive skills, but there is a certain amount of learning and catch-up that needs to take place with children who have experienced a hearing loss prior to cochlear implantation," study author William Kronenberger, a professor of clinical psychology in psychiatry, said in a university news release.

"So far, most of the interventions to help with this learning have focused on speech and language. Our findings show a need to identify and help some children in certain domains of executive functioning as well," he added.

Study co-author David Pisoni, director of the university's Speech Research Laboratory, said the team now is looking for early signs of risk in children before they get implants.

"It will be beneficial to identify as early as possible which children might be at risk for poor outcomes, and we need to understand the variability in the outcome and what can be done about it," he added in the news release.